Apparatus for producing variable amplitude vibratory force

ABSTRACT

The present invention provides an apparatus for producing a variable amplitude vibratory force which is particularly useful as a rotatable eccentric for a vibratory roller. The rotatable eccentric comprises first and second eccentric fluid chambers rotatable about a common axis of rotation, and adjustable valve means interconnecting the chambers for controlling the amount of fluid transfer between the chambers upon rotation of the eccentric to produce a variable amplitude vibratory force.

United States Fatent Ebersole APPARATUS FOR PRODUCHNG VARKABLE AMPLHTUDEVHERATORY FO RCE D. Henry Ebersole, Springfield,

Ohio I Assignee: Koehring Company, Milwaukee,

Wis.

Filed: Oct. 19, 1972 Appl. No.: 299,059

[75] Inventor:

US. Cl. 74/61, 198/220 DB, 74/87 Int. Cl. F1611 33/00 Field 011 Search.74/61, 87, 573;

References Cited UNITED STATES PATENTS 9/1958 Nauta t. 74/61 June 4,1974 Kahn 74/573 Carrier, Jr. I98/220 DB Primary ExaminerSamuel ScottAssistant Examiner-Wesley S. Ratliff, Jr. Attorney, Agent, or FirmAndrew J. Beck [5 7 ABSTRACT The present invention provides an apparatusfor producing a variable amplitude vibratory force which is particularlyuseful as a rotatable eccentric for a vibratory roller. The rotatableeccentric comprises first and second eccentric fluid chambers rotatableabout a common axis of rotation, and adjustable valve means 1interconnecting the chambers for controlling the amount of fluidtransfer between the chambers upon rotation .of the eccentric to producea variable amplitude vibiatory force.

30 Claims, 7 Drawing Figures NENTEHJUN 4m: Q 331335 Sam 1 m d F/Q Zagelsgso PMENYEMH 4 1914 SHEU 3 (If Q l I APPARATUS FOR PRODUCINGVARIABLE AMPLITUDE VIBRATORY FORCE The present invention relates to anapparatus for producing a variable amplitude vibratory force and, moreparticularly, to a rotatable eccentric for use in a vibratory roller toproduce a variable amplitude vibratory force upon rotation.

In the art of vibratory rollers, it is well known to use a rotatableeccentric device mounted for rotation about the axis of a vibratoryroller to impart a vibratory force to the roller. In the prior art,vibrating devices incorporating liquid filled eccentric weights havebeen.

weights. The manual arrangements have not been capable of precise andautomatic control of the fluid transfer.

The present invention provides a rotatable eccentric for use in avibratory roller to produce a variable amplitude vibratory force capableof precise adjustment. In contrast to the devices of the prior art, therotatable eccentric requires no external control devices and operatesautomatically in response to centrifugal forces generated upon rotationof the eccentric.

In accordance with the present invention, a rotatable eccentric forproducing a variable amplitude vibratory force upon rotation comprisesfirst and second eccentric fluid chambers rotatable about a common axisof rotation, and adjustable valve means interconnecting the chambers forcontrolling the amount of fluid transfer between the chambers uponrotation of the eccentric to produce a variable amplitude vibratoryforce. In a preferred embodiment, the first chamber is a fluid reservoircomprising a hollow cylinder having closed ends with its axis displacedfrom the common axis of rotation, and the second chamber is mounted onthe cylinder on the opposite side of the axis of rotation from the axisof the cylinder. Preferably, the adjustable valve means comprises aninlet member mounted at one end of the cylinder having an inlet orificein fluid communication with the interior of the cylinder and capable ofmovement between various radial positions relative to the axis ofrotation for receivingfluid upon rotation of the eccentric, and meansfor selectively moving the inlet member to adjust the inlet orifice between its various radial positions to control the amount of fluidtransfer from the first chamber to the second chamber.

An alternative embodiment of the rotatable eccentric of the presentinvention includes a fluid reservoir chamber and an eccentric fluidchamber rotatable about a common axis of rotation, first adjustablevalve means interconnecting the reservoir chamber and the eccentricchamber for controlling the amount of fluid transferred from thereservoir chamber to the eccentric chamber under the action ofcentrifugal forces generated upon rotation of the eccentric to produce avariable amplitude vibratory force, and second adjustable valve meansinterconnecting the reservoir chamber and the eccentric chamber forpermitting a portion of the fluid transferred from the reservoir chamberto the eccentric chamber during rotation of the eccentric to return bygravity to the reservoir chamber upon termination of the rotation.

The rotatable eccentric of the present invention eliminates therequirement of an external control device for controlling fluidtransfer. In addition, the eccentric permits an infinitely variablevibratory force to be obtained.

The accompanying drawings illustrate a preferred embodiment of theinvention and, together with the description, serve to explain theprinciples of the invention.

In the drawings:

FIG. I is a longitudinal section of a vibratory roller illustrating arotatable eccentric constructed in accordance with the principles of thepresent invention comprising a fluid reservoir, an eccentric fluidchamber, and adjustable valve means interconnecting the eccentric fluidchamber and reservoir.

FIG. 2 is a vertical section of the rotatable eccentric taken along line22 of FIG. 1.

FIG. 3 is an end view of the vibratory roller of FIG. I.

.FIG. 4 is a sectional view of an alternative embodiment of theadjustable valve means of the rotatable eccentric of the presentinvention.

FIG. 5 is a vertical section, similar to FIG. 2, of the rotatableeccentric of FIG. 4 showing a front view of the adjustable valve means.

FIG. 6 is a front elevation, partially in section, illustrating anotherrotatable eccentric constructed in accordance with the principles of thepresent invention including a fluid reservoir chamber, an eccentricfluid chamber, and adjustable valve means in both the reservoir chamberand the eccentric chamber.

FIG. 7 is an end view of the rotatable eccentric of FIG. 6.

Referring to FIG. 1, a vibratory roller, generally 20, is mounted forrotation between a pair of transversely spaced roller support arms 22and 24 of a compacting device (not shown) by a pair of bearingassemblies 26 and 28, respectively. A pair of shaft portions 30 and 32is rotatably supported by bearing assemblies 26 and 28, respectively.The bearing assemblies include conventional bearing arrangements (notshown) to permit roller 20 to rotate relative to roller support arms 22and 24 and-to permit rotation of shaft portions 30 and 32 relative tothe roller. A pair of rotatable counterweights 34 and 36 is mounted onshaft portions 30 and 32, respectively, within bearing assemblies 26 and28.

Vibratory roller 20 comprises a pair of circular end walls 38 and 40 anda cylindrical shell 42 mounted peripherally on end walls 38 and 40 forcompacting engagement with a surface S. End wall 38 is provided with acentral circular opening 44 for receiving bearing assembly 26.Similarly, end wall 40 is provided with a central circular opening 46for receiving bearing assembly 28. Vibratory roller 20 is thus mountedfor rotation about its axis by bearing assemblies 26 and 28. Inaddition, end wall 38 is provided with an opening 48 to allow easyaccess to the interior of vibratory roller 20.

As shown in FIG. I, a rotatable eccentric, generally 50, constructed inaccordance with the-principles of the present invention, is mounted onshaft portions'3ll and 32 for rotation about the axis of vibratoryroller 20. A fluid motor (not shown) is coupled to one of the shaftportions to impart rotation to the eccentric.

In accordance with the invention, the rotatable eccentric for producinga variable amplitude vibratory force comprises first and secondeccentric fluid chambers rotatable about a common axis of rotation. In apreferred embodiment, the geometric axes of the chambers are located atdiametrically opposed positions relative to the axis of rotation and arespaced at different distances from the axis of rotation. As embodied andshown in FIG. l, rotatable eccentric 55) includes a first fluid chamber54 comprising a hollow cylinder 56 provided with circular end plates 58and 60 to close the ends of the cylinder. A sleeve @2 is mounted on endplate 58 at a position displaced from the axis of the cylinder and iscoupled to shaft portion 30 by a pair of pins 6 3. .Similarly, a sleeveas is mounted on end plate 60 in axial alignment with sleeve 62 and iscoupled to shaft portion 32 by a pair of pins 68.

Rotatable eccentric 50 also includes a second fluid chamber 70comprising a generally rectangular housing 72 and rectangular end walls74 and 76. As shown in FIGS. l and 2, rectangular housing 72 and endwalls 74 and 76 are mounted in fluid-tight engagement on the outersurface of cylinder 56 at a position diametrically opposed to the axisof cylinder 56 in relation to the roller axis. Chamber 54 acts as afluid reservoir to supply fluid'to eccentric chamber 70.

In accordance with the invention, the rotatable eccentric includesadjustable valve means interconnecting the chambers for controlling theamount of fluid transfer between the chambers upon rotation of theeccentric to produce a variable amplitude vibratory force. Asillustrated in the embodiment shown in FIG. l, a control valve,generally 80, is mounted on end plate 58 of cylinder 56. The controlvalve includes an inlet member in the form of a tube 82 rotatablymounted in a passage provided in a valve block 34 secured to end plate58. Inlet tube $2 extends into cylinder 56 through a passage provided inend plate 58. The inlet tube includes a bent portion 86 provided with aninlet orifice 88 capable of movement between various radial positionswithin cylinder 56 relative to the axis of rotation. A handle 90 iscoupled to the opposite end of tube '82 to enable the tube to beselectively rotated. Handle 90 thus provides means for selectivelymoving the inlet member, i.e., rotatable tube 82, to adjust inletorifice 88 between its various radial positions.

As shown in FIG. 1, valve block 84 includes a passageway 92 extendingfrom the passage in the valve block for receiving inlet tube 82 to thelower end of the valve block. Tube 82 is provided with an opening (notshown) in fluid communication with passageway 92 to permit fluidadmitted to tube 82 through inlet orifice 88 to flow into thepassageway.

Conduit means for coupling the adjustable valve means to the secondfluid chamber is embodied as a conduit 94 extendingfrom the lower end ofvalve block 8 3 to a fluid inlet as provided in housing '72 of eccentricfluid chamber 70. Conduit 94 permits fluid transfer from reservoirchamber t through inlet tube 82, passageway 92 and fluid inlet 96 toeccentric fluid chamber 70. An air vent in the form of a tube 97extending through the side wall of cylinder 56 is provided to permit airlocated within reservoir chamber 54 and eccentric chamber to bedisplaced between the chambers upon fluid transferto equalize thepressures in the chambers.

A baffle plate 98 (FIGS. 1 and 2) is mounted within reservoir chamber54. The baffle plate extends radially inward from the lower portion ofthe side wall of cylinder 56. A plurality of struts 99 (FIG. -1) isprovided to maintain baffle plate 98 in a rigid position within thecylinder. The purpose of the baffle plate is to restrict fluid movementin the reservoir chamber during rotation of eccentric 50. As shown inFIG. 1, baffle plate 9% includes a plurality of spaced openings 100formed in its lower edge to allow limited flow to opposite sides of thebaffle plate.

In a preferred embodiment of the rotatable eccentric, conduit means isprovided for coupling the first and second chambers to permit fluidtransferred from the first chamber to the second chamber during rotationof the eccentric to drain into the first chamber upon termination of therotation. As shown in FIGS. 1 and 2, this conduit means is embodied inrotatable eccentric 50 as a pair of ball check valves 101 and 102mounted in openings formed in cylinder 56 at the lower end of chamber70. Referring to FIG. 2, ball check valve 101 comprises a hollowcylindrical body 104 having an opening 105 of reduced size at its upperend to provide a valve seat. A ball 106 is located within hollowcylindrical body 104, and a pin 107 extends across the hollowcylindrical body at its lower end. Upon rotation of eccentric 50, ball106 is driven by centrifugal force into contact with the valve seat toprevent fluid flow from eccentric chamber 70 to reservoir chamber 54.When rotation of the eccentric is terminated, ball 106 drops into a restposition in contact with pin 107 to permit fluid transferred toeccentric chamber 70 to drain into reservoir chamber 54. Ball checkvalve 102 is identical in structure and operation to ball check valve101.

In operation of the rotatable eccentric of FIG. 1, a predeterminedamount of fluid is supplied to reservoir chamber 54. Control valve isthen operated by rotating handle to position inlet orifice 88 ofrotatable tube 82 in a desired radial position relative to the axis ofrotation. Upon operation of the fluid motor (not shown), rotatableeccentric 50 is rotated about the axis of the vibratory roller. Therotation of eccentric 50 causes the fluid in reservoir chamber 54 toadopt a generally annular configuration (indicated by shaded region 108in FIG. 2) about the axis of rotation of chamber 54 as a result ofcentrifugal forces exerted on the fluid. The fluid located in region 108flows through inlet orifice 88 of tube 82, passageway 92, conduit 94,and inlet opening 926 into eccentric chamber 70 until, as shown in FIG.2, the inner radius of the fluid in annular region l08 coincides withthe radial distance of inlet orifice 88 from the axis of rotation. Thisradial distance can be selectively varied by rotation of handle 90 tomove inlet orifice 88 of tube 82 to different radial positions withinreservoir chamber 54 to thereby control the amount of fluid transferredfrom the reservoir chamber to eccentric chamber 70.

The fluid transferred to eccentric chamber 70 also adopts a generallyannular configuration (indicated by shaded region ill) in FIG. 2). Thisfluid constitutes an eccentric weight that is rotated about the axis ofvibratory roller 20. Thus, upon rotation of eccentric 50 about the axisof roller 21), a vibratory force is imparted to the roller having anamplitude determined by the amount of fluid transferred to eccentricchamber 78 and the magnitude of counterweights 34 and 36. The amplitudeof the vibratory force produced by eccentric 50 can be preciselyadjusted by rotating handle 90 of control valve 80 to change theposition of inlet orifice 88 of tube 82 in reservoir chamber 54 to varythe amount of fluid transferred to eccentric chamber 70. Thus, theamplitude of the total vibratory force imparted to roller 211 can beincreased or decreased by adjustment of the control valve.

In the embodiment of the rotatable eccentric of FIGS. 4 and 5, analternative arrangement is provided for securing sleeve 62 to cylinder56. Referring to F110 4, a circular opening 118 is formed in end plate58 of cylinder 56 at a position spaced from the common axis of thecylinder and end plate. Sleeve 62 extends through opening 118 and issecured to end plate 58 in a conventional manner, such as by welding. Asimilar arrangement (not shown) is provided at the opposite end ofcylinder 56 for securing sleeve 66 (FIG. 2) to the cylinder.

In addition, the rotatable eccentric of FIGS. 4, and 5 incorporates analternative embodiment of the adjustable valve means of the presentinvention. Referring to FIG. 4, a control valve, generally 128, ismounted on end plate 58 of cylinder 56. The end plate is provided with acircular opening 122 for receiving a generally circular valve block 124of the control valve. The valve block is provided with a peripheralgroove for mounting an O-ring seal 125 in sealing engagement with theside wall of circular opening 122. In addition, valve block 124 isprovided with an axial passage 126 for rotatably receiving a shaft 128.Shaft 128 includes a pcripheral groove for mounting an O-ring seal 130in sealing engagement with the interior wall of passage 126.

Control valve 120 includes an inlet member in the form of a disc 132(FIGS. 4 and 5) provided with an inlet orifice 134 extending completelythrough the disc at a position spaced radially from the disc axis. Valveblock 124 is provided with a cylindrical recess 136 formed on its frontsurface for receiving disc 132. The disc is supported on the inner endof shaft 128 for rotation in cylindrical recess 136. Disc 132 includes apcripheral groove formed along its outer surface for mounting an O-ringseal 138 in sealing engagement with the interior cylindrical wall ofrecess 136.

As shown in FIG. 4, the outer end of shaft 128 comprises a sleeve 140including a pair of circular openings 142 formed at diametricallyopposed positions adjacent to the end of the sleeve. A lock nut 144 isprovided to maintain shaft 128 within passage 126 of valve block 124.Shaft 128 is provided with an axial bore for receiving a bolt 146 tosecure disc 132 to the opposite, inner end of shaft 128. Referring toFIG. 5, a handle 148 is fitted in openings 142 of sleeve 1411 to providemeans for selectively moving the inlet member, i.e., rotatable disc 132,to adjust inlet orifice 134 between various radial positions relative tothe axis of rotation.

Valve block 124 (FIG. 4) includes a first passageway 150 extendingaxially from recess 136 and a second passageway 152 extending radiallyfrom passageway 150 to the lower end of the valve block. Passageways 150and 152 receive fluid admitted into recess 136 through inlet orifice 134of disc 132.

Conduit means for-coupling the adjustable valve means to the secondfluid chamber is embodied as a conduit 154 extending from the lower endof valve block 124 to a fluid inlet 156-(FIG. 5) provided in the housingof eccentric fluid chamber 70. Conduit 154 permits fluid transfer fromreservoir chamber 54 through orifice 134 of rotatable disc 132, recess136, passageways 1511 and 152, and fluid inlet 156 to the eccentricfluid chamber. As shown in FIG. '5, the rotatable eccentric includes apair of ball check valves 101 and 1112 identical in structure andoperation to the ball check valves of the rotatable eccentric of FIG. 2.

The operation of the rotatable eccentric of FIGS. 4 and 5 issubstantially the same as the operation of the rotatable eccentric ofFIGS. 1 and 2 previously described. Initially, a predetermined amount offluid is supplied to reservoir chamber 54. Control valve is thenoperated by rotating handle 148 to position inlet orifice 134 ofrotatable disc 132 in a desired radial position relative to the axis ofrotation.

When the eccentric is rotated, the fluid in reservoir chamber 54 adopt agenerally annular configuration (indicated by shaded region 158 in FIG.5) about the axis of rotation of reservoir chamber 54 as a result ofcentrifugal forces exerted on the fluid. The fluid located in region 158flows through inlet orifice 134 of disc 132, recess 136 and passagewaysand 152 in valve block 124, conduit 154, and fluid inlet 156 intoeccentric chamber 70 until, as shown in FIG. 5, the inner radius of thefluid in annular region 158 coincides with the radial distance of inletorifice 134 from the axis of rotation. This radial distance can beselectively varied by rotation of handle 148 to move inlet orifice 134to different radial positions within reservoir chamber 54 to therebycontrol the amount of fluid transferred from the reservoir chamber toeccentric chamber 70. i

The fluid transferred to eccentric chamber 70 also adopts a generallyannular configuration (indicated by shaded region 160 in FIG. 5). Thisfluid constitutes an eccentric weight that produces vibratory forces asa result of rotation of the eccentric. The amplitude of the vibratoryforce produced by the eccentric can be precisely adjusted by rotatinghandle 148 of control valve 120 to change the position of inlet orifice134 of disc 132 in reservoir chamber 54 to vary the amount of fluidtransferred to eccentric chamber 70. Thus, control valve 121) permitsthe amplitude of the vibratory forces generated by the eccentric to beselectively increased or decreased as desired.

FIGS. 6 and 7 illustrate an alternative embodiment of the rotatableeccentric of the present invention including a fluid reservoir chamberand an eccentric fluid chamber rotatable about a common axis ofrotation, and adjustable valve means located in both the reservoirchamber and the eccentric chamber. Referring to FIG. 6, fluid reservoirchamber 54 and eccentric fluid chamber 70 are identified by the samereference numerals used in the discussion of the previous embodiments.Reservoir chamber 54 is provided by cylinder 56 having end plates 58 and60 secured at its opposite ends. Sleeves 62 and 66 are mounted on endplates 58 and 611, respectively, at positions displaced from the axis ofcylinder 56 to support the eccentric for rotation about the axis of avibratory roller (not shown). Eccentric fluid chamber 70 is provided bya generally rectangular housing 72 including end plates 74 and 76. The

eccentric chamber is mounted on cylinder 56 on the opposite side of theaxis of rotation from the axis of the cylinder.

An air vent in the form of a tube 97 mounted in opening formed incylinder 56 is provided for interconnecting reservoir chamber 54 andeccentric chamber 70 to allow air displacement between the reservoir andeccentric chambers. In addition, a baffle plate 98 is mounted withinreservoir chamber 54. The baffle plate extends radially inward from thelower portion of the side wall of cylinder 56, and a plurality of struts99 is provided to maintain the baffle plate in a rigid position in thecylinder. The purpose of baffle plate 98 is to restrict fluid movementin cylinder 56 during rotation of the eccentric. Baffle plate 98includes a plurality of spaced openings 190 formed in its lower edge toallow limited fluid flow to opposite sides of the baffle plate.

In 'accordance with the invention, the eccentric includes firstadjustable valve means interconnecting the reservoir chamber and theeccentric chamber for controlling the amount of fluid transferred fromthe reservoir chamber to the eccentric chamber under the action ofcentrifugal forces generated upon rotation of the eccentric to produce avariable amplitude vibratory force. The first adjustable valve means isembodied in the rotatable eccentric of FIG. 6 as a first control valve,generally 181), substantially identical to control valve 120 of FIG. 4.Control valve 180 (FIG. 6) includes an inlet member in the form ofarotatable disc 182 having an inlet orifice 184 in fluid communicationwith reser voir chamber54. Inlet orifice 184 extends completely throughrotatable disc 182 at a position spaced radially from the axis of thedisc.

Disc 182 is received in a recess 186 formed in a valve block 188 mountedin an opening provided in end plate 58. A shaft 190 is rotatablyreceived in an axial passage formed in valve block 188. A gear wheel 192is secured to the outer end of shaft 190, and disc 182 is supported onthe opposite end of the shaft for rotation in recess 186. A firstpassageway 194 extends axially from recess 186 into valve block 188, anda second passageway 196 extends radially from passageway 194 to thelower end of the valve block.

First conduit means for coupling the first adjustable valve means to theeccentric chamber is embodied as a conduit 198 extending from the lowerend of valve block 188 to a fluid inlet 2011 provided in housing 72 ofeccentric chamber 70. Conduit 198 permits fluid to be transferred fromreservoir chamber 54 through orifice 184 of disc 182, recess 186,passageways 194 and 196, and fluid inlet 200 to the eccentric chamber.

In accordance with the invention, the rotatable eccentric includessecond adjustable valve means interconnecting the reservoir chamber andthe eccentric chamber for permitting a portion of the fluid transferredfrom the reservoir chamber to the eccentric chamber during rotation ofthe eccentric to return by gravity to the reservoir chamber upontermination of the rotation. As embodied in FIG. 6, a second controlvalve, generally 210, similar to control valve 180, is provided ineccentric fluid chamber 711. Control valve 210 includes an inlet memberin the form ofa rotatable disc 212 having an inlet orifice 214 in fluidcommunication with eccentr'ic fluid chamber 70. Inlet orifice 214extends completely through disc 212 at a position spaced radially fromthe axis of the disc.

Disc 212 is received in a recess 216 formed in a valve block 218 mountedin an opening provided in end wall 74. A sleeve 222 (FIG. 6) extendsoutward from valve.

block 218, and a shaft 224 is rotatably received within sleeve 222 andan axial passage provided in the valve block. A gear wheel 226 issecured to the outer end of shaft 224 and disc 212 is supported on theopposite end of the shaft for rotation in recess 216. Gear wheel 226 ofcontrol valve 210 is located in vertical alignment with gear wheel 192of control valve 180.

Second conduit means for coupling the second adjustable valve means tothe interior of the cylinder is embodied as tube 220 extending downwardfrom recess 216 into reservoir chamber 54 through openings provided invalve block 218 and cylinder 56. Tube 220 allows fluid received byrecess 216 through inlet orifice 214 of disc 212 to return by gravity tocylinder 56.

As shown in FIG. 6, adial 228 is mounted on shaft 224 for rotation withthe shaft and gear wheel 226. The dial is provided with markers (notshown) for indicating the position of inlet orifice 214 in eccentricchamber 70. A pointer 230 is mounted on sleeve 222 and extends acrossthe top of dial 228 to allow adjustment of control valve 210 to set itsinlet orifice to a desired position by rotating dial 228 to align thecorresponding marker on the dial with the pointer.

A chain 232 (FIGS. 6 and 7) is provided for coupling gear wheels 192 and226 to rotate the gear wheels simultaneously upon rotation of dial 228..As shown in FIG. 7, control valves 180 and 210 are arranged to positioninlet orifice 214 of rotatable disc 212 in its lowermost position ineccentric chamber when inlet orifree 184 of disc 182 is located in itsuppermost position in reservoir chamber 54. On the other hand, wheninlet orifice 214 of rotatable disc 212 is located in its uppermostposition in eccentric chamber 70, inlet orifice 184 of disc 182 islocated in its lowermost position in the reservoir chamber. In addition,by rotation of dial 228, inlet orifices 184 and 214 can besimultaneously adjusted to an infinite number of intermediate positions.

In the operation of the rotatable eccentric of FIGS. 6 and 7, apredetermined amount of fluid is supplied to reservoir chamber 54.Control valves and 210 are then simultaneously operated by rotating dial228 to position inlet orifices 184 and 214 of rotatable discs 182 and212, respectively, in desired radial positions relative to the axis ofrotation. When the eccentric is rotated, the fluid in reservoir chamber54 adopts a generally annular configuration about the axis .of rotationas the result of centrifugal forces exerted on the fluid. The fluidlocated in the reservoir chamber. flows through inlet orifice 184 ofdisc 182, recess 186 and passageways 194 and 196 in valve block 188,conduit 198 and fluid inlet 200 until the inner radius of the fluid inthe annular region in reservoir chamber 54 coincides with the radialdistance of inlet orifice 184 from the axis of rotation. This radialdistance can be selectively varied by rotation of dial 228 to move inletorifice 184 to difierent radial positions within reservoir chamber 54 tocontrol the amount of fluid transferred from the reservoir chamber toeccentric chamber 70.

The fluid transferred to eccentric chamber 70 also adopts a generallyannular configuration during rotation of the eccentric. This fluidconstitutes an eccentric weight that produces vibratory forces as aresult of rotation of the eccentric. The amplitude of the vibratoryforce produced by the eccentric can be precisely adjusted by rotatingdial 228 to change the position of inlet orifice H84 in reservoirchamber 541 to vary the amount of fluid transferred to eccentric chamber70. Thus, by adjustment of control valve 210 to move inlet orifice 184between its various radial positions, the amplitude of the vibratoryforce produced upon rotation of the eccentric can be increased ordecreased as desired.

When rotation of the eccentric is terminated, the amount of fluid. thatreturns from eccentric chamber 70 to reservoir chamber 54 is determinedby setting of control valve 210. When, as shown in FIG. 7, inlet orifice214 of control valve 210 is located in its lowermost position, all ofthe fluid transferred from reservoir chamber 54 to eccentric chamber 70through control valve 180 during rotation of the eccentric will returnby gravity to the reservoir chamber. When inlet orifice 214 of controlvalve 210 is located in any other position, however, only a portion ofthe fluid transferred from reservoir chamber 54 to eccentric chamber 70will return by gravity through control valve 210 to the reservoirchamber. Thus, an amount of fluid determined by the setting of valve 210will remain in eccentric chamber 70 even though rotation of theeccentric is completely terminated. Thereafter, when rotation of theeccentric is resumed, the fluid returned to reservoir chamber 54 fromeccentric chamber 70 will again be transferred to the eccentric chamberthrough control valve 180 to produce vibratory forces of a desiredamplitude.

By preventing all of the fluid transferred to eccentric chamber 70during rotation of the eccentric from returning to reservoir chamber 54when the eccentric is temporarily stopped, the embodiments of FIGS. 6and 7 permits the amplitude of the vibratory forces produced by theeccentric to be stabilized at a desired level. This embodiment thusallows a repeated start and stop operation of the eccentric with aminimum amount of fluid flow between the eccentric chamber to thereservoir chamber.

The invention in its broader aspects is not limited to the specificdetails shown and described, and modifications may be made in thedetails of the rotatable eccentric without departing from the principlesof the present invention.

What is claimed is:

1. A compacting device, comprising:

a support;

a roller rotatably mounted on said support; and

a rotatable eccentric mounted within said roller for rotation about theroller axis independently of said roller to produce a variable amplitudevibratory force upon rotation, said eccentric comprising first andsecond fluid chambers each eccentrically rotatable about the roller axisindependently of rotation of said roller and adjustable valve meansinterconnecting said chambers for controlling the amount of. fluidtransfer between said chambers upon rotation of said eccentric toproduce a variable amplitude vibratory force.

2. The compacting device of claim 1, wherein the geometric axes of saidchambers are located at diametrically opposed positions relative to theroller axis and spaced at different distances from the roller axis. 3.The compacting device of claim 1, wherein:

said first chamber comprises a hollow cylinder having closed ends withits axis displaced from the roller axis; and

said second chamber is mounted on said cylinder on the opposite side ofthe roller axis from the axis of said cylinder.

4. The compacting device of claim 3, wherein said adjustable valve meanscomprises:

an inlet member mounted at one end of said cylinder having an inletorifice in fluid communication with the interior of said cylinder andcapable of movement between various radial positions relative to theroller axis for receiving fluid from said cylinder upon rotation of theeccentric; and

means for selectively moving said inlet member to adjust said inletorifice between its various radial positions to control the amount offluid transfer from said first chamber to said second chamber.

5. The compacting device of claim 4, wherein:

said inlet member of said adjustable valve means comprises a tuberotatably mounted in an opening formed at one end of said cylinder, saidtube including a bent portion at one of its ends extending into saidcylinder to provide said inlet orifice; and which includes conduit meansfor coupling said adjustable valve means to said second fluid chamber topermit fluid received from said first chamber through said inlet orificeto be transferred to said second chamber upon rotation of saideccentric.

6. The compacting device of claim 5, wherein:

said means for moving said inlet member comprises a handle connected tothe opposite end of said tube for rotating the bent portion of said tubeto various radial positions.

7. The compacting device of claim 4, wherein:

said inlet member of said adjustable valve means comprises a discrotatably mounted in an opening formed at one end of said cylinder, saidinlet orifice extending completely through said disc at a positionspaced radially from the axis of said disc; and which includes conduitmeans for coupling said adjustable valve means to said second fluidchamber to permit fluid received from said first chamber through saidinlet orifice to be transferred to said second, chamber upon rotation ofsaid eccentric.

8. The compacting device of claim 4, wherein:

said adjustable valve means includes a valve block mounted in an openingformed at one end of said cylinder, said valve block including a recessformed on its front surface in fluid communication with the interior ofsaid cylinder;

said inlet member comprises a disc rotatably mounted in said recessformed in said valve block, said inlet orifice extending completelythrough said disc at a position spaced radially from the axis of saiddisc; and which includes conduit means for coupling said adjustablevalve means to said second fluid chamber to permit fluid admitted intosaid recess in said valve block through said inlet orifice to betransferred to said second chamber upon rotation of said eccentric.

9. The compacting device of claim 1, which includes:

conduit means for coupling said first and second chambers to permitfluid transferred from said first ill chamber to said second chamberduring rotation of said eccentric to drain into said first chamber upontermination of the rotation. 10. The compacting device of claim 1, whichincludes:

an air vent for interconnecting said first and second chambers to permitair located within said chambers to be displaced between said chambersduring fluid transfer upon rotation of said eccentric. ill. Thecompacting device of claim 3, which includes:

a baffle plate extending radially inward from the interior of saidcylinder for restricting fluid movement in said cylinder during rotationof eccentric.

12. A compacting device, comprising:

a support;

a vibratory roller mounted on said support for rotation about its axis;and

a rotatable eccentric mounted within said roller for rotation about theroller axis independently of said roller to produce-a variable amplitudevibratory force, said rotatable eccentric comprising an eccentric fluidchamber rotatable about the roller axis for producing a vibratory forceupon rotation;

a fluid reservoir rotatable about the roller axis for supplying fluid tosaid eccentric fluid chamber under the action of centrifugal forcesgenerated upon rotation of said reservoir; and

adjustable valve means interconnecting said eccentric fluid chamber andsaid reservoir for controlling the amount of fluid transfer from saidreservoir to said eccentric fluid chamber as a result of the centrifugalforces to permit the amplitude of the vibratory force to be adjusted. I

13. The compacting device of claim 12, wherein said adjustable valvemeans of said rotatable eccentric comprises:

an inlet member having an inlet orifice in fluid communication with saidreservoir and capable of movement between-various radial positionsrelative to the roller axis for receiving fluid under the action of thecentrifugal forces generated upon rotation of said reservoir; and

means for selectively moving said inlet member to adjust said inletorifice between its various radial positions to control the amount offluid transfer from said reservoir to said eccentric fluid chamber.

14. The compacting device of claim 13, wherein said rotatable eccentricincludes:

conduit means for coupling said adjustable valve means to said eccentricfluid chamber to permit fluid transfer through said inlet member fromsaid reservoir to said eccentric chamber.

15. The compacting device of claim 13, wherein:

said inlet member of said adjustable valve means comprises a tuberotatably mounted in an opening formed at one end of said fluidreservoir, said tube including a bent portion at one of its endsextending into said fluid reservoir to provide said inlet orifree; and

6 conduit means for coupling said ad ustable valve means to saideccentric fluid chamber to permit fluid received from said fluidreservoir through said inlet orifice to be transferred to said eccentricfluid chamber upon rotation of said eccentric.

16. The compacting device of claim 15, wherein:

said means for selectively moving said inlet member comprises a handleconnected to the opposite end of said tube for rotating the bent portionof said tube to various-radial positions in said fluid reservoir; and

said vibratory roller'includes an opening formed in one of its sides toallow access to said handle.

17. The compacting device of claim 13, wherein:

said inlet member of said adjustable valve means comprises a discrotatably mounted in an opening formed at one end of said fluidreservoir, said inlet orifice extending completely through said disc ata position spaced radially from the axis of said disc; and whichincludes conduit means for coupling said adjustable valve means to saideccentric fluid chamber to permit fluid received from said fluidreservoir through said inlet orifice to be transferred to said eccentricfluid chamber upon rotation of said eccentric.

18. The compacting device of claim 12, wherein said rotatable eccentricincludes:

conduit means for coupling said eccentric fluid chamber to saidreservoir to permit fluid transferred from said reservoir to saidchamber during rotation of said eccentric to drain into said reservoirupon termination of the rotation.

19. The compacting device of claim 12, wherein: said fluid reservoircomprises a cylindrical chamber having its axis displaced from theroller axis; and said eccentric fluid chamber is mounted on saidcylindrical chamber at a position diametrically opposed to the axis ofsaid cylindrical chamber in relation to the roller axis. 20. Thecompacting device of claim 12, which includes:

counterweight means mounted for rotation with said eccentric about theaxis of the vibratory roller. 21. A rotatable eccentric for producing avariable amplitude vibratory force upon rotation, comprising:

a fluid reservoir chamber and an eccentric fluid chamber rotatable abouta common axis of rotation;

first adjustable valve means interconnecting said reservoir chamber andsaid eccentric chamber for controlling the amount of fluid transferredfrom said reservoir chamber to said eccentric chamber under the actionof centrifugal forces generated upon rotation of the eccentric toproduce a variable amplitude vibratory force; and

second adjustable'valve means interconnecting said reservoir chamber andsaid eccentric chamber for permitting a portion of the fluid transferredfrom said reservoir chamber to said eccentric chamber during rotation ofthe eccentric to return by gravity to said reservoir chamber upontermination of the rotation.

22. The rotatable eccentric of claim 21, wherein the geometric axes ofsaid fluid reservoir chamber and said eccentric chamber are located atdiametrically opposed positions relative to the axis of rotation andspaced at different distances from the axis of rotation.

23. The rotatable eccentric of claim 21, wherein:

said fluid reservoir chamber comprises a hollow cylinder having closedends with its axis displaced from the common axis of rotation; and

said eccentric chamber is mounted on said cylinder on the opposite sideof the axis of rotation from the axis of said cylinder.

24. The rotatable eccentric of claim 21, wherein:

said first adjustable valve means includes a first inlet member havingan inlet orifice in fluid communication with said fluid reservoirchamber and capable of movement between various radial positions in saidfluid reservoir chamber relative to the axis of rotation for receivingfluid from said fluid reservoir chamber upon rotation of the eccentric;and

said second adjustable valve means includes a second inlet member havingan inlet orifice in fluid communication with said eccentric chamber andcapable of movement between various radial positions in said eccentricchamber relative to the axis of rotation for receiving fluid from saideccentric chamber upon termination of rotation of the eccentric; andwhich includes first conduit means for coupling said first adjustablevalve means to said eccentric chamber to permit fluid received by saidfirst inlet member to be transferred to eccentric chamber; and

second conduit means for coupling said second adjustable valve means tosaid fluid reservoir chamber to permit fluid received by said secondinlet member to be returned by gravity to said fluid reservoir chamber.

25. The rotatable eccentric of claim 23, wherein:

said first adjustable valve means includes a first valve block mountedin an opening formed at one end of said cylinder, said first valve blockincluding a recess formed on its front surface in fluid communicationwith the interior of said cylinder, and a first disc rotatably mountedin said recess formed in said first valve block having a first inletorifice extending completely through said first disc at a posi tionspaced radially from the axis of said first disc; and

said second adjustable valve means comprises a second valve blockmounted in an opening formed at one end of said eccentric chamber, saidsecond valve block including a recess formed on its front surface influid communication with the interior of said eccentric chamber, and asecond disc rotatably mounted in said recess formed in said second valveblock having a second inlet orifice extending completely through saidsecond disc at a position spaced radially from the axis of said seconddisc; and which includes conduit means for coupling said firstadjustable'valve means to said eccentric chamber to permit fluidadmitted into said recess in said first valve block through said firstinlet orificeto be transferred to said eccentric chamber upon rotationof the eccentric; and

second conduit means for coupling said second adjustable valve means tothe interior of said cylinder to permit fluid admitted into said recessin said second valve block through said second inlet orifice to betransferred to said cylinder upon termination of the rotation of theeccentric.

26. The rotatable eccentric of claim 25, which includes:

means for simultaneously rotating said first and second discs to adjustsaid first and second inlet orifices to desired radial positions.

27. The rotatable eccentric of claim 26, wherein:

said first adjustable valve means includes a shaft rotatably received ina passage extending through said first valve block for supporting saidfirst disc for rotation in said recess formed in said first valve block;

said second adjustment valve means includes a second shaft rotatablyreceived in a passage extending through said second valve block forsupporting said second disc for rotation in said recess formed in saidsecond valve block; and

said means for simultaneously rotating said first and second discsincludes a first gear wheel secured to said first shaft, a second gearwheel secured to said second shaft, and a chain for connecting saidfirst and second gear wheels for simultaneous rotation.

28.The rotatable eccentric of claim 23, which includes:

a bafile plate extending radiallydnward from the interior of saidcylinder for restricting fluid movement in said cylinder during rotationof the eccentric. 29. A compacting device, comprising: a support; aroller rotatably mounted on said support; and a rotatable eccentricmounted within said roller for rotation about the roller axisindependently of said roller to produce a variable amplitude vibratoryforce upon rotation, said eccentric comprising first and second fluidchambers eccentrically rotatable about the roller axis independently ofrotation of said roller; and

fluid conduit means interconnecting said chambers, said fluid conduitmeans including an inlet member located in said first chamber andmovable between various positions in said first chamber for controllingthe amount of fluid transfer from said first chamber to said secondchamber upon rotation of said eccentric to produce a variable amplitudevibratory force.

30. A compacting device, comprising:

a support;

a vibratory roller mounted on said support for rotation about its axis;

a rotatable eccentric mounted within said roller for rotation about theroller axis independently of the roller to produce a variable amplitudeforce, said rotatable eccentric comprising an eccentric fluid chamberrotatable about the roller axis for producing a vibratory force uponrotation;

a fluid reservoir'rotatable about the roller axis for supplying fluid tosaid eccentric fluid chamber under the action of centrifugal forcesgenerated upon rotation of said reservoir; and

fluid conduit means interconnecting said eccentric fluid chamber andsaid reservoir, said fluid conduit means including an inlet memberlocated in said reservoir and movable between various positions in saidreservoir for controlling the amount of fluid transfer from saidreservoir to said eccentric fluid chamber as a result of the centrifugalforces to permit the amplitude of the vibratory force to be adjusted.

1. A compacting device, comprising: a support; a roller rotatablymounted on said support; and a rotatable eccentric mounted within saidroller for rotation about the roller axis independently of said rollerto produce a variable amplitude vibratory force upon rotation, saideccentric comprising first and second fluid chambers each eccentricallyrotatable about the roller axis independently of rotation of said rollerand adjustable valve means interconnecting said chambers for controllingthe amount of fluid transfer between said chambers upon rotation of saideccentric to produce a variable amplitude vibratory force.
 2. Thecompacting device of claim 1, wherein the geometric axes of saidchambers are located at diametrically opposed positions relative to theroller axis and spaced at different distances from the roller axis. 3.The compacting device of claiM 1, wherein: said first chamber comprisesa hollow cylinder having closed ends with its axis displaced from theroller axis; and said second chamber is mounted on said cylinder on theopposite side of the roller axis from the axis of said cylinder.
 4. Thecompacting device of claim 3, wherein said adjustable valve meanscomprises: an inlet member mounted at one end of said cylinder having aninlet orifice in fluid communication with the interior of said cylinderand capable of movement between various radial positions relative to theroller axis for receiving fluid from said cylinder upon rotation of theeccentric; and means for selectively moving said inlet member to adjustsaid inlet orifice between its various radial positions to control theamount of fluid transfer from said first chamber to said second chamber.5. The compacting device of claim 4, wherein: said inlet member of saidadjustable valve means comprises a tube rotatably mounted in an openingformed at one end of said cylinder, said tube including a bent portionat one of its ends extending into said cylinder to provide said inletorifice; and which includes conduit means for coupling said adjustablevalve means to said second fluid chamber to permit fluid received fromsaid first chamber through said inlet orifice to be transferred to saidsecond chamber upon rotation of said eccentric.
 6. The compacting deviceof claim 5, wherein: said means for moving said inlet member comprises ahandle connected to the opposite end of said tube for rotating the bentportion of said tube to various radial positions.
 7. The compactingdevice of claim 4, wherein: said inlet member of said adjustable valvemeans comprises a disc rotatably mounted in an opening formed at one endof said cylinder, said inlet orifice extending completely through saiddisc at a position spaced radially from the axis of said disc; and whichincludes conduit means for coupling said adjustable valve means to saidsecond fluid chamber to permit fluid received from said first chamberthrough said inlet orifice to be transferred to said second chamber uponrotation of said eccentric.
 8. The compacting device of claim 4,wherein: said adjustable valve means includes a valve block mounted inan opening formed at one end of said cylinder, said valve blockincluding a recess formed on its front surface in fluid communicationwith the interior of said cylinder; said inlet member comprises a discrotatably mounted in said recess formed in said valve block, said inletorifice extending completely through said disc at a position spacedradially from the axis of said disc; and which includes conduit meansfor coupling said adjustable valve means to said second fluid chamber topermit fluid admitted into said recess in said valve block through saidinlet orifice to be transferred to said second chamber upon rotation ofsaid eccentric.
 9. The compacting device of claim 1, which includes:conduit means for coupling said first and second chambers to permitfluid transferred from said first chamber to said second chamber duringrotation of said eccentric to drain into said first chamber upontermination of the rotation.
 10. The compacting device of claim 1, whichincludes: an air vent for interconnecting said first and second chambersto permit air located within said chambers to be displaced between saidchambers during fluid transfer upon rotation of said eccentric.
 11. Thecompacting device of claim 3, which includes: a baffle plate extendingradially inward from the interior of said cylinder for restricting fluidmovement in said cylinder during rotation of eccentric.
 12. A compactingdevice, comprising: a support; a vibratory roller mounted on saidsupport for rotation about its axis; and a rotatable eccentric mountedwithin said roller for rotation about the roller axis independently ofsaid roller to produce a variable amplitude vibratory forcE, saidrotatable eccentric comprising an eccentric fluid chamber rotatableabout the roller axis for producing a vibratory force upon rotation; afluid reservoir rotatable about the roller axis for supplying fluid tosaid eccentric fluid chamber under the action of centrifugal forcesgenerated upon rotation of said reservoir; and adjustable valve meansinterconnecting said eccentric fluid chamber and said reservoir forcontrolling the amount of fluid transfer from said reservoir to saideccentric fluid chamber as a result of the centrifugal forces to permitthe amplitude of the vibratory force to be adjusted.
 13. The compactingdevice of claim 12, wherein said adjustable valve means of saidrotatable eccentric comprises: an inlet member having an inlet orificein fluid communication with said reservoir and capable of movementbetween various radial positions relative to the roller axis forreceiving fluid under the action of the centrifugal forces generatedupon rotation of said reservoir; and means for selectively moving saidinlet member to adjust said inlet orifice between its various radialpositions to control the amount of fluid transfer from said reservoir tosaid eccentric fluid chamber.
 14. The compacting device of claim 13,wherein said rotatable eccentric includes: conduit means for couplingsaid adjustable valve means to said eccentric fluid chamber to permitfluid transfer through said inlet member from said reservoir to saideccentric chamber.
 15. The compacting device of claim 13, wherein: saidinlet member of said adjustable valve means comprises a tube rotatablymounted in an opening formed at one end of said fluid reservoir, saidtube including a bent portion at one of its ends extending into saidfluid reservoir to provide said inlet orifice; and conduit means forcoupling said adjustable valve means to said eccentric fluid chamber topermit fluid received from said fluid reservoir through said inletorifice to be transferred to said eccentric fluid chamber upon rotationof said eccentric.
 16. The compacting device of claim 15, wherein: saidmeans for selectively moving said inlet member comprises a handleconnected to the opposite end of said tube for rotating the bent portionof said tube to various radial positions in said fluid reservoir; andsaid vibratory roller includes an opening formed in one of its sides toallow access to said handle.
 17. The compacting device of claim 13,wherein: said inlet member of said adjustable valve means comprises adisc rotatably mounted in an opening formed at one end of said fluidreservoir, said inlet orifice extending completely through said disc ata position spaced radially from the axis of said disc; and whichincludes conduit means for coupling said adjustable valve means to saideccentric fluid chamber to permit fluid received from said fluidreservoir through said inlet orifice to be transferred to said eccentricfluid chamber upon rotation of said eccentric.
 18. The compacting deviceof claim 12, wherein said rotatable eccentric includes: conduit meansfor coupling said eccentric fluid chamber to said reservoir to permitfluid transferred from said reservoir to said chamber during rotation ofsaid eccentric to drain into said reservoir upon termination of therotation.
 19. The compacting device of claim 12, wherein: said fluidreservoir comprises a cylindrical chamber having its axis displaced fromthe roller axis; and said eccentric fluid chamber is mounted on saidcylindrical chamber at a position diametrically opposed to the axis ofsaid cylindrical chamber in relation to the roller axis.
 20. Thecompacting device of claim 12, which includes: counterweight meansmounted for rotation with said eccentric about the axis of the vibratoryroller.
 21. A rotatable eccentric for producing a variable amplitudevibratory force upon rotation, comprising: a fluid reservoir chamber andan eccentric fluid chamber rOtatable about a common axis of rotation;first adjustable valve means interconnecting said reservoir chamber andsaid eccentric chamber for controlling the amount of fluid transferredfrom said reservoir chamber to said eccentric chamber under the actionof centrifugal forces generated upon rotation of the eccentric toproduce a variable amplitude vibratory force; and second adjustablevalve means interconnecting said reservoir chamber and said eccentricchamber for permitting a portion of the fluid transferred from saidreservoir chamber to said eccentric chamber during rotation of theeccentric to return by gravity to said reservoir chamber upontermination of the rotation.
 22. The rotatable eccentric of claim 21,wherein the geometric axes of said fluid reservoir chamber and saideccentric chamber are located at diametrically opposed positionsrelative to the axis of rotation and spaced at different distances fromthe axis of rotation.
 23. The rotatable eccentric of claim 21, wherein:said fluid reservoir chamber comprises a hollow cylinder having closedends with its axis displaced from the common axis of rotation; and saideccentric chamber is mounted on said cylinder on the opposite side ofthe axis of rotation from the axis of said cylinder.
 24. The rotatableeccentric of claim 21, wherein: said first adjustable valve meansincludes a first inlet member having an inlet orifice in fluidcommunication with said fluid reservoir chamber and capable of movementbetween various radial positions in said fluid reservoir chamberrelative to the axis of rotation for receiving fluid from said fluidreservoir chamber upon rotation of the eccentric; and said secondadjustable valve means includes a second inlet member having an inletorifice in fluid communication with said eccentric chamber and capableof movement between various radial positions in said eccentric chamberrelative to the axis of rotation for receiving fluid from said eccentricchamber upon termination of rotation of the eccentric; and whichincludes first conduit means for coupling said first adjustable valvemeans to said eccentric chamber to permit fluid received by said firstinlet member to be transferred to eccentric chamber; and second conduitmeans for coupling said second adjustable valve means to said fluidreservoir chamber to permit fluid received by said second inlet memberto be returned by gravity to said fluid reservoir chamber.
 25. Therotatable eccentric of claim 23, wherein: said first adjustable valvemeans includes a first valve block mounted in an opening formed at oneend of said cylinder, said first valve block including a recess formedon its front surface in fluid communication with the interior of saidcylinder, and a first disc rotatably mounted in said recess formed insaid first valve block having a first inlet orifice extending completelythrough said first disc at a position spaced radially from the axis ofsaid first disc; and said second adjustable valve means comprises asecond valve block mounted in an opening formed at one end of saideccentric chamber, said second valve block including a recess formed onits front surface in fluid communication with the interior of saideccentric chamber, and a second disc rotatably mounted in said recessformed in said second valve block having a second inlet orificeextending completely through said second disc at a position spacedradially from the axis of said second disc; and which includes conduitmeans for coupling said first adjustable valve means to said eccentricchamber to permit fluid admitted into said recess in said first valveblock through said first inlet orifice to be transferred to saideccentric chamber upon rotation of the eccentric; and second conduitmeans for coupling said second adjustable valve means to the interior ofsaid cylinder to permit fluid admitted into said recess in said secondvalve block through said second inlet orifice to be transfErred to saidcylinder upon termination of the rotation of the eccentric.
 26. Therotatable eccentric of claim 25, which includes: means forsimultaneously rotating said first and second discs to adjust said firstand second inlet orifices to desired radial positions.
 27. The rotatableeccentric of claim 26, wherein: said first adjustable valve meansincludes a shaft rotatably received in a passage extending through saidfirst valve block for supporting said first disc for rotation in saidrecess formed in said first valve block; said second adjustment valvemeans includes a second shaft rotatably received in a passage extendingthrough said second valve block for supporting said second disc forrotation in said recess formed in said second valve block; and saidmeans for simultaneously rotating said first and second discs includes afirst gear wheel secured to said first shaft, a second gear wheelsecured to said second shaft, and a chain for connecting said first andsecond gear wheels for simultaneous rotation.
 28. The rotatableeccentric of claim 23, which includes: a baffle plate extending radiallyinward from the interior of said cylinder for restricting fluid movementin said cylinder during rotation of the eccentric.
 29. A compactingdevice, comprising: a support; a roller rotatably mounted on saidsupport; and a rotatable eccentric mounted within said roller forrotation about the roller axis independently of said roller to produce avariable amplitude vibratory force upon rotation, said eccentriccomprising first and second fluid chambers eccentrically rotatable aboutthe roller axis independently of rotation of said roller; and fluidconduit means interconnecting said chambers, said fluid conduit meansincluding an inlet member located in said first chamber and movablebetween various positions in said first chamber for controlling theamount of fluid transfer from said first chamber to said second chamberupon rotation of said eccentric to produce a variable amplitudevibratory force.
 30. A compacting device, comprising: a support; avibratory roller mounted on said support for rotation about its axis; arotatable eccentric mounted within said roller for rotation about theroller axis independently of the roller to produce a variable amplitudeforce, said rotatable eccentric comprising an eccentric fluid chamberrotatable about the roller axis for producing a vibratory force uponrotation; a fluid reservoir rotatable about the roller axis forsupplying fluid to said eccentric fluid chamber under the action ofcentrifugal forces generated upon rotation of said reservoir; and fluidconduit means interconnecting said eccentric fluid chamber and saidreservoir, said fluid conduit means including an inlet member located insaid reservoir and movable between various positions in said reservoirfor controlling the amount of fluid transfer from said reservoir to saideccentric fluid chamber as a result of the centrifugal forces to permitthe amplitude of the vibratory force to be adjusted.